Hi

I would like to know the **exact rule** for creating binary selector.
Because | works but || or |< does not.


Where can I find this information?

Stef


Dr. Stéphane DUCASSE (ducasse at iam.unibe.ch) 
http://www.iam.unibe.ch/~ducasse/
  "if you knew today was your last day on earth, what would you do
  different? ... especially if, by doing something different, today
  might not be your last day on earth" Calvin&Hobbes